iPod Touch 4 won't power on

Won't power on / black screen. May be battery may be ipod. It wasn't mine got it with cracked screen and replaced. Thinking of replacing the battery too. Not really sure won't even go to charging screen. Home/Power doesn't work either.

I disconnected the and plugged in ipod it in and it powered on. Then I reconnected the battery. Looks like it was stuck in some kinda limbo state. I ordered a battery before I did that so oops.... look like I'll have an extra battery for a repair in the future. ...